How is the polar stereographic projection defined ?
The north polar stereographic projection is an azimuthal projection. It can be imagined as a plane surface crossing the earth surface. If a light source inside the globe projects the graticule onto the plane, the result would be a planar, or azimuthal, map projection. In the Canadian Wind Energy Atlas, we define that plane as the one crossing the earth at a latitude of 60 degrees North with a projection made from a point at the south pole (light source). This projection can be viewed as seeing the earth from above the North pole. This projection is convenient for domains close to latitude 60N toward the pole but deformations become important away from this latitude, especially going toward the equator. It is well suited for Canada. We represent the earth as a sphere of radius Rt. Let us consider a point on the earth surface located by its longitude Λ and its latitude Φ. In the polar plane, this point will be located by a radius (distance to the centre) and a polar angle Θ. The followin
